New local hyperthermia using dextran magnetite complex (DM) for oral cavity: experimental study in normal hamster tongue

Abstract

The possibility of dextran magnetite complex (DM) as a new hyperthermic material was examined in this study. DM suspension of 56 mg ml(-1) iron concentration was locally injected into the normal tongue of golden hamster. DM injected tongues were heated by 500 kHz alternating current (AC) magnetic field and its serial changes in temperature were recorded at 30-s intervals. The temperature of DM injected tongue was maintained at about 43.0-45.0 degrees C for 30 min by changing the AC magnetic field intensity. While temperature elevations of the contralateral tongue and the rectum were only of minor degree. In experiment on the extent of heating area, there was correlation between volume of black stain area and amount of the injected DM suspension (Y = - 18.1 + 1.94X, r = 0.931, P < 0.0001, n = 9 ). Histological examination after heating revealed brown uniform DM accumulation in the connective tissue between fibers of the tongue muscle. Except for vascular dilatations, no tissue damage was seen in the heated tongue. Thus, DM which has the possibility of selective and uniform heating in local hyperthermia might be useful for oral cancer therapy.

Magnetic Nanoparticles and Their Applications in Medicine

“…Stability improvement may be achieved when dextran macromolecules are cross-linked in a second step for enhancing the mechanical entrapment of magnetic cores (cross-linked iron oxide [CLIO] [28]) or when dextran macromolecules are chemically bonded to magnetic cores through the use of coupling agents [29] (versatile USPIO [VUSPIO] [30]). (U)SPIO pharmacokinetics, toxicity and biodistribution properties were studied and allowed to define the potential uses of these contrast agents [31][32][33][34][35]. The lethal dose (LD 50 ) of the dextran-iron oxide complex was found to be 2000-6000 mg Fe /kg of body, whereas it is 300-600 mg Fe /kg for pristine iron oxide [35].…”

“…(U)SPIO pharmacokinetics, toxicity and biodistribution properties were studied and allowed to define the potential uses of these contrast agents [31][32][33][34][35]. The lethal dose (LD 50 ) of the dextran-iron oxide complex was found to be 2000-6000 mg Fe /kg of body, whereas it is 300-600 mg Fe /kg for pristine iron oxide [35]. The nanoparticles are metabolized in lysosomes and the soluble iron becomes part of the normal iron pool (e.g., ferritin, hemosiderin, transferritin and hemoglobin) [26,36].…”

Magnetically Modulated Nanosystems: A Unique Drug-Delivery Platform

“…Some researchers have proposed the concept of 'intracellular' hyperthermia and have developed submicron MPs for inducing hyperthermia [61].…”

A new method to destruct targeted cells using magnetizable beads and pulsed magnetic force

“…Furthermore, these modalities are also ineffective for deep-seated tumors, in which only invasive methods using implanted antennas are available. Recently, hyperthermia using harmless magnetizable particles as a method to treat targeted tumors has been reported [5]- [7]. Additional research on the magnetic targeting of drug delivery for specific tissues [8] and antibody-targeted chemotherapy [9] are promising, but there is still the possibility that the drugs, which circulate throughout the body before reaching targeted tissues, can damage normal tissues.…”